Skin is subject to deterioration through dermatological disorders, environmental abuse (wind, air conditioning, central heating) or through the normal aging process (chronoaging) which may be accelerated by exposure of skin to sun (photoaging). In recent years the demand for cosmetic compositions and cosmetic methods for improving the appearance and condition of skin has grown enormously.
Consumers are increasingly seeking "anti-aging" cosmetic products which treat or delay the visible signs of chronoaging and photoaging skin such as wrinkles, lines, sagging, hyperpigmentation and age spots.
Consumers also frequently seek other benefits from cosmetic products in addition to anti-aging. The concept of "sensitive skin" has also raised the consumer demand for cosmetic products which improve the appearance and condition of sensitive, dry, rough and/or flaky skin and to soothe red, irritated and/or itchy skin. Consumers also desire cosmetic products which treat spots, pimples, blemishes etc.
Skin care cosmetic and dermatological compositions for improving the condition and appearance of skin comprising long chain triglyceride esters of polyunsaturated essential fatty acids, the free acids and their alkali or ammonium salts are well known in the art. For instance, GB 2181349 A describes inter alia a composition composed of triglycerides of linoleic acid for improving the smoothness and elasticity of skin. A commercial product, "Linola Fett n" ex Dr. August Wolff Gmbh, is available for the treatment of dry skin diseases, and dermatoses, which contains inter alia a mixture of the 9,11 isomers of conjugated linoleic acid.
There continues to be a need, however, for alternative effective cosmetic compositions for topical application to skin for treating/delaying the visible signs of aging and photodamaged skin such as wrinkles, lines, sagging, hyperpigmentation and age spots. Compositions and cosmetic methods which provide other skin care benefits in addition to anti-aging such as for improving the appearance and condition of dry, rough and flaky skin and to soothe irritated and itchy skin are particularly desirable.
We have now surprisingly found that effective treatment and prevention of normal skin conditions due to chronoaging or photoaging, such as wrinkles, lines, sagging, hyperpigmentation and age spots, and/or of sensitive, dry, rough, flaky, red, itchy, irritated skin may be obtained through the application of cosmetic compositions to the skin which are specifically enriched in a particular isomer of conjugated linoleic acid or derivatives thereof.